A kind of for Ag + A quinoline fluorescent probe for detecting and its preparation method and application

Abstract

This invention discloses a method for Ag + This paper discusses quinoline fluorescent probes for detection, their preparation methods, and applications. It aims to address existing methods for detecting Ag. + The existing fluorescent probes suffer from technical problems such as low sensitivity, long response time, short fluorescence wavelength, small Stokes shift, and poor biocompatibility. This invention addresses these issues with the detection of Ag. + The structure of the quinoline-based fluorescent probe for detection is as follows: it is obtained by reacting 6-(dimethylamino)quinoline-2-carboxaldehyde with aminothiourea to obtain a Schiff base intermediate, followed by a cyclization addition reaction with bromoacetophenone. This intermediate is then used as a fluorescent probe for Ag... + Qualitative and quantitative detection. Unaffected by coexisting ions in the environment and unaffected by acidic or alkaline conditions. Can be used for Ag... + Testing field.

Description

Technical Field

[0001] This invention belongs to the field of silver ions (Ag) + In the field of Ag detection, specifically involving a method for Ag detection + Quinoline fluorescent probes for detection, their preparation methods, and applications. Background Technology

[0002] Silver ions (Ag) + Ag possesses unique biological properties, including antibacterial, antiviral, antioxidant activity, immune-enhancing, and metabolism-promoting effects. + It can accelerate wound healing by stimulating cell proliferation around the wound and has shown therapeutic effects on eye infections, skin ulcers, and burn-related infections. Silver nanoparticles further serve as a multifunctional drug delivery platform. In addition to biomedical applications, Ag... + It also possesses excellent ductility, electrical conductivity, and thermal conductivity, making it suitable for various industrial applications in fields such as chemical engineering, electronics, and photography. However, prolonged exposure to Ag... + It can trigger harmful physiological reactions, including immunosuppression, neurological dysfunction, endocrine disorders, gastric mucosal damage, liver degeneration, and systemic inflammation. Ag + Accumulation of silver ions in the environment poses a significant risk to ecosystems, impacting plant growth and threatening aquatic life. Therefore, sensitive detection of silver ions in biological and environmental samples is crucial for both clinical diagnosis and environmental monitoring.

[0003] Traditional Ag + Detection methods mainly include colorimetry, gas chromatography, electrochemical methods, atomic absorption spectrometry, gel electrophoresis, and inductively coupled plasma mass spectrometry. However, these techniques generally suffer from problems such as expensive equipment, complex operation, or slow response speed. Fluorescent probe technology has attracted much attention in environmental science, biomedicine, and virology research due to its excellent specificity, low toxicity, and real-time dynamic monitoring capabilities. However, existing small-molecule fluorescent probes often suffer from poor photostability, low sensitivity, slow response speed, and poor anti-interference properties. Fluorescence imaging can non-invasively observe subtle concentration changes of ions and small-molecule biological substances in biological systems, providing important diagnostic information for disease progression. However, there are relatively few existing red fluorescent probes that can suppress background interference, have low biotoxicity, and cause minimal optical damage to biological tissues. Ye Fei et al. reported a naphthalimide-based fluorescent probe in the March 2019 issue (Volume 200) of *Talanta*, which can completely quench Ag by green fluorescence. + It allows for selective recognition, but the probe only responds to Ag under neutral and alkaline conditions. + And the probe recognizes Ag + Its detection limit is relatively high (1.20 µM), which to some extent limits its ability to detect trace amounts of Ag.+ Detection applications.

[0004] In analytical chemistry, Schiff base probes are indispensable tools due to their excellent coordination ability, tunable photophysical properties, and ease of structural modification. Notably, heteroatoms in these molecules can serve as strong recognition sites for metal ions, leading to stable chelate formation. In recent years, researchers have continuously explored novel Schiff base probes, but challenges remain, including low sensitivity and slow response speed. Liu Kai et al. reported a coumarin Schiff base probe in the June 2024 issue (No. 278) of *Talanta*, demonstrating its ability to recognize Ag through red fluorescence quenching. + However, this probe can recognize Hg through the same fluorescence response. 2+ (Specificity is not ideal), and the probe identifies Ag. + The probe has relatively low sensitivity (detection limit of 0.25 µM) and poor water solubility (the volume ratio of solvent acetonitrile to water is 4:1). In addition, the probe cannot be used for bioimaging due to toxicity or biocompatibility factors, which greatly limits its application in the biological field for trace Ag. + Detection applications.

[0005] According to current literature reports, for Ag + The identification methods mainly have the following drawbacks: 1. Used for Ag + The fluorescent probe being detected emits a relatively short wavelength; 2. Existing methods for Ag + The sensitivity and response speed of the detected fluorescent probes are not ideal; 3. Existing methods for Ag + The detected fluorescence can be made into test strips and combined with smartphone recognition technology for Ag. + Probes for real-time detection are relatively scarce.

[0006] 4. Existing methods for Ag + There are relatively few fluorescent probes that can be used for in vivo imaging of mice. Summary of the Invention

[0007] The present invention aims to solve the existing problems used for Ag + The fluorescent probe used for detection has a short emission wavelength, low sensitivity, and slow response speed, and is ineffective against Ag in environmental water samples. + To address technical issues such as the inability to perform real-time detection and low biocompatibility, a method for Ag is provided. + This paper describes a quinoline-based fluorescent probe for silver ion detection, its preparation method, and its application. This quinoline-based fluorescent probe exhibits novel structure, good stability, high sensitivity, strong anti-interference properties, and good biocompatibility, enabling its detection of Ag. +Qualitative detection and bioimaging applications.

[0008] The present invention is for Ag + The structure of the quinoline-based fluorescent probe being detected is as follows:

[0009] The above is used for Ag + The quinoline fluorescent probe used for detection is a Schiff base intermediate obtained by reacting 6-(diaminomethyl)quinoline-2-carboxaldehyde with aminothiourea. The reaction formula is as follows:

[0010] Then, a cyclization addition reaction is carried out between the Schiff base intermediate and bromoacetophenone to obtain the product used for Ag. + The reaction formula for the quinoline-based fluorescent probe being detected is as follows:

[0011] The above-mentioned use for Ag + The preparation method of the quinoline-based fluorescent probe for detection is carried out according to the following steps: I. Quinolinaldehyde monomer and aminothiourea are added to solvent I in a molar ratio of (1~2):1. Then, acid is added to solvent I as a catalyst in a molar ratio of quinolinaldehyde monomer to acid of 1:(0.01~0.1). The mixture is stirred evenly to obtain reaction solution I. The quinolinaldehyde monomer is 6-(dimethylamino)quinoline-2-carboxaldehyde. 2. Add reaction solution I to the round-bottom flask, and perform a vacuum-nitrogen-purging cycle on the round-bottom flask to maintain a nitrogen environment inside the round-bottom flask; 3. Raise the temperature of the round-bottom flask to 60-80℃ and maintain it for 8-14 hours to carry out the reaction; IV. After the reaction is complete, the mixture is cooled to room temperature, filtered, and the filter cake is washed clean with mixed solvent II and dried under vacuum to obtain the Schiff base intermediate. V. Add the Schiff base intermediate and bromoacetophenone to an organic solvent at a molar ratio of (1~1.3):1, and react under reflux for 10~14 h. VI. After the reaction is complete, filter the mixture. Wash the filter cake with mixed solvent II, and dry it under vacuum to obtain the product used for Ag. + The quinoline-based fluorescent probes used for detection.

[0012] Furthermore, the method for synthesizing the quinoline aldehyde monomer described in step one is as follows: (1) First, N,N-dimethyl-p-phenylenediamine was added to concentrated hydrochloric acid, and then butenaldehyde was added dropwise to the system. The reaction was carried out at room temperature for 1 hour to obtain a pale yellow solid 6-(dimethylamino)-2-methylquinoline intermediate. (2) Add 6-(dimethylamino)-2-methylquinoline intermediate and 4.5 g selenium dioxide to 20 mL xylene and react at 145 °C for 3-6 hours to obtain 6-(dimethylamino)quinoline-2-carboxaldehyde; The chemical trans form for the synthesis of quinoline aldehyde monomers is as follows:

[0013]

[0014] Furthermore, solvent I mentioned in step one is any one of ethanol, methanol, toluene, and dioxane.

[0015] Furthermore, the acid mentioned in step one is glacial acetic acid, trifluoroacetic acid, p-toluenesulfonic acid, concentrated hydrochloric acid with a mass percentage concentration of 30% to 37%, or concentrated sulfuric acid with a mass percentage concentration of 95% to 98%.

[0016] Furthermore, the molar ratio of the acid to the quinolinaldehyde monomer mentioned in step one is (0.01~0.1):1.

[0017] Furthermore, the mixed solvent II mentioned in steps four and six is ​​tetrahydrofuran, methanol, ethanol, ethyl acetate, acetone, or chloroform.

[0018] Furthermore, the organic solvent mentioned in step five is tetrahydrofuran, acetone, methanol, or ethanol.

[0019] The above-mentioned use for Ag + The application of quinoline fluorescent probes for detection is to use them as fluorescent probes for Ag. + Qualitative detection.

[0020] Using the above-mentioned method for Ag + The fluorescent probe for detection was subjected to Ag + The qualitative detection method is carried out according to the following steps: I. To be used for Ag + The quinoline fluorescent probes for detection were uniformly dispersed in a mixture of HEPES buffer solution (pH 7.4) and dimethyl sulfoxide (DMSO) at a volume ratio of 8:2, yielding probe solution A. Probe solution A was then used to detect Ag... + The concentration of the quinoline fluorescent probes used for detection was 5–10 µM; 2. Add the sample to be tested, I, to the probe solution A and mix them evenly to obtain the test solution B; III. Using 430 nm as the excitation wavelength, measure the fluorescence emission spectrum of probe solution A, and record the emission intensity at an emission wavelength of 580 nm, denoted as T. A ; IV. Using 430 nm as the excitation wavelength, measure the fluorescence emission spectrum of the test solution B, and record the emission intensity at an emission wavelength of 580 nm, denoted as T. B ; V. Comparison of T A and T B If T B >T A If so, it is determined that the sample to be tested contains Ag. + .

[0021] An invention for Ag + Compared with existing technologies, the beneficial effects of the quinoline fluorescent probes for detection, their preparation methods, and applications are as follows: The quinoline-based fluorescent probes of the present invention serve as fluorescent probes for Ag. + It exhibits strong specificity and anti-interference ability, and is able to target Ag. + To achieve recognition without interference from other competing ions, such as Fe. 3+ Cu 2+ Cd 2+ Zn 2+ Ca 2+ , Cr 3+ Ag + Mg 2+ Al 3+ Ni 2+ Ba 2+ Co 2+ , Pb 2+ Fe 2+ and Hg 2+ Furthermore, it is unaffected by acidic or alkaline environments. Compared to other fluorescent probes, the quinoline-based fluorescent probes of this invention can be applied to the detection of Ag in environmental water samples and mice. + This advancement in bioimaging expands the application range of quinoline-based fluorescent probes. The quinoline-based fluorescent probes of this invention can be used to detect Ag. + The method is simple and has a rapid response. During the test, the quinoline fluorescent probe can maintain a stable fluorescence intensity, indicating that it has good optical stability and its recognition performance is not affected by the external environment. Attached Figure Description

[0022] Figure 1 It is the preparation of Ag prepared in Example 1 + High-resolution mass spectra of the detected quinoline fluorescent probes; Figure 2 It is the preparation of Ag prepared in Example 1+ The 1H NMR spectrum of the detected quinoline fluorescent probe; Figure 3 It is the preparation of Ag prepared in Example 1 + Fluorescence spectra of the detected quinoline fluorescent probes and the addition of different types of cations, with wavelength on the x-axis and fluorescence intensity on the y-axis; Figure 4 It is the preparation of Ag prepared in Example 1 + The detected quinoline fluorescent probes competed with different types of cations and Ag. + Fluorescence spectrum during coexistence, with wavelength on the horizontal axis and fluorescence intensity on the vertical axis; Figure 5 It is the preparation of Ag prepared in Example 1 + The detected quinoline fluorescent probes and different concentrations of Ag + Fluorescence spectrum during coexistence, with wavelength on the horizontal axis and fluorescence intensity on the vertical axis; Figure 6 It is the preparation of Ag prepared in Example 1 + The detected quinoline fluorescent probes and different concentrations of Ag + A linear fitting plot of fluorescence intensity during coexistence, with the x-axis representing Ag. + Concentration, with fluorescence intensity on the ordinate; Figure 7 It is the preparation of Ag prepared in Example 1 + The detected quinoline fluorescent probe and Ag + Fluorescence intensity graphs under different pH conditions during coexistence, with pH value on the x-axis and fluorescence intensity on the y-axis; Figure 8 It is the preparation of Ag prepared in Example 1 + The detected quinoline fluorescent probe and Ag + Fluorescence intensity graphs at different times during coexistence, with pH value on the x-axis and fluorescence intensity on the y-axis.

[0023] Figure 9 It is the preparation of Ag prepared in Example 1 + The quinoline-based fluorescent probe test strip, combined with a smartphone, can detect Ag in environmental water samples (lake water and industrial wastewater). + Semi-quantitative analysis.

[0024] Figure 10 It is the preparation of Ag prepared in Example 1 + Cytotoxicity curve of the detected quinoline fluorescent probes. The horizontal axis represents Ag. + Concentration, with the vertical axis representing the percentage of cell survival; Figure 11 (A) is the preparation of Ag prepared in Example 1. +The quinoline-based fluorescent probes detected exogenous Ag in live mice. + (A) Fluorescence imaging image; (B) Average fluorescence intensity of the imaging site. Detailed Implementation

[0025] The beneficial effects of the present invention are verified using the following examples: Example 1: This example is used for Ag + The preparation method of the quinoline fluorescent probe for detection is carried out according to the following steps: 1. Add 1 mmol of quinoline aldehyde monomer and 1 mmol of aminothiourea to 20 mL of ethanol solvent I, and then add 0.01 mol of glacial acetic acid as a catalyst. Mix well to obtain reaction solution I. The quinoline aldehyde monomer is synthesized according to the following steps: (1) First, add 5 g of N,N-dimethyl-p-phenylenediamine to 60 mL of concentrated hydrochloric acid with a mass percentage of 30%~37%, then add 5 mL of butenaldehyde to the system, and react at room temperature for 1 hour to obtain a pale yellow solid 6-(dimethylamino)-2-methylquinoline intermediate; (2) Add 6-(dimethylamino)-2-methylquinoline intermediate and 4.5 g selenium dioxide to 20 mL xylene and react at 80 °C for 4 hours to obtain 6-(dimethylamino)quinoline-2-carboxaldehyde; 2. Add reaction solution I to the round-bottom flask, and perform a vacuum-nitrogen-purging cycle on the round-bottom flask to maintain a nitrogen environment inside the round-bottom flask; 3. Raise the temperature of the round-bottom flask to 65°C and maintain it for 8 hours to carry out the reaction; IV. After the reaction was completed, the mixture was cooled to room temperature and filtered. The filter cake was washed clean with a mixed solvent II containing tetrahydrofuran and methanol in a volume ratio of 1:1. After vacuum drying, a Schiff base intermediate with a mass of 0.18 g was obtained. 5. Add 0.5 mmol of Schiff base intermediate and 0.5 mmol of bromoacetophenone to 10 mL of anhydrous ethanol, and react under reflux for 8 hours; VI. After the reaction is complete, the mixture is filtered. The filter cake is washed three times with a mixed solvent II containing tetrahydrofuran and ethanol in a volume ratio of 1:1. After vacuum drying, the product is obtained for use with Ag. + The mass of the quinoline fluorescent probe detected was 0.079 g.

[0026] The preparation of Ag in this embodiment + Mass spectrometry of the detected quinoline fluorescent probes and their performance in deuterated DMSO solvent 1 The HNMR spectral data are as follows: 1 H NMR (DMSO-d 6,400 MHz) δ (ppm): 13.26 (s, 1H), 8.58 (d, J =8 Hz,1H), 8.28(s, 1H), 8.05 (d, J =12 Hz, 1H), 7.99 (d, J =12 Hz, 1H), 7.87 (d, J =8Hz, 2H), 7.65 (d, J =8 Hz, 1H), 7.52 (s, 1H), 7.45 (t, J =8 Hz, 2H), 7.35 (t, J =8 Hz, 1H), 7.13(s, 1H), 3.09 (s, 6H). 13 C NMR (DMSO- d 6, 100 MHz) δ (ppm):167.35, 150.02, 144.36, 141.06, 134.57, 130.15, 129.15, 128.29, 126.00,122.89, 117.89, 106.16, 105.12, 40.46. HR-MS (positive mode m / z) for C 21 H 19 N5S: calcd: 374.46703, found: 374.46752 The characterization results above show that the Ag prepared in this embodiment is effective. + The structure of the detected quinoline fluorescent probe is as follows:

[0027] The Ag prepared in Example 1 + The spectral performance of the detected quinoline-based fluorescent probes was tested using the following steps: I. Solution preparation: According to Ag + The concentration of the quinoline fluorescent probe being detected was 1×10⁻⁶. -4 M will be used for Ag + The quinoline fluorescent probes to be detected were uniformly dispersed in dimethyl sulfoxide to obtain probe solution A; Weigh 0.017 g of silver nitrate as Ag. +The source was added to a 10 mL volumetric flask, and the solution was diluted to volume with a mixture of HEPES buffer solution (pH 7.4) and dimethyl sulfoxide (DMSO) at a volume ratio of 8:2. The mixture was then sonicated until completely dissolved, yielding a solution with a concentration of 1 × 10⁻⁶. -2 M's Ag + Stock solution; Different masses of metal salts (ferric nitrate, copper sulfate, cadmium nitrate, zinc chloride, calcium chloride, chromium chloride, silver nitrate, magnesium sulfate, aluminum chloride, nickel chloride, barium sulfate, cobalt nitrate, lead sulfate, ferrous chloride, and mercuric chloride) were weighed and added to 10 mL volumetric flasks. The solutions were then diluted to volume with a mixture of HEPES buffer solution (pH 7.4) and dimethyl sulfoxide (DMSO) at a volume ratio of 8:2. The solutions were sonicated until completely dissolved, yielding a concentration of 1 × 10⁻⁶. -2 Different types of metal ion storage solutions of M; II. Spectral performance testing: Different types of metal ion stock solutions were added to 10 µM probe solution A, and the solutions were ultrasonically vibrated for 5 min to obtain mixed solutions. Using 430 nm as the excitation wavelength, the fluorescence emission spectra of 10 µM probe solution A and different types of metal ion stock solutions with 20 µM added were measured. The results are as follows: Figure 3 As shown. By Figure 3 It can be seen that the fluorescence emission wavelength of probe solution A prepared in this embodiment is 480 nm, and the fluorescence intensity is 8.5 × 10⁻⁶. 4 au. Add 20 µM Ag + After the stock solution was applied, the emission wavelength shifted significantly from 480 nm to 560 nm, and the fluorescence intensity significantly increased to 1.37 × 10⁻⁶. 5 au; however, after adding other different types of competing metal ion stock solutions, the fluorescence wavelength and fluorescence intensity of probe solution A remained almost unchanged. Therefore, based on the fluorescence emission spectrum, it can be inferred that the fluorescent probe prepared in this embodiment is effective against Ag. + It has selective recognition capabilities.

[0028] The probe solution A of Test Example 1 was tested in Ag + The detection method for resisting interference from different types of metal ions is as follows: Add 20 µM of different types of metal ion stock solutions to 10 µM probe solution A, shake well, and then add 20 µM of Ag. + The stock solution was prepared into a mixed test solution containing the probe, the recognition substance, and the interfering substance. After thorough mixing, the solution was sonicated for 5 minutes, followed by fluorescence testing. The results are as follows: Figure 4 As shown. From Figure 4 It can be seen that Ag+ When coexisting with different types of competing metal ions, the fluorescence intensity of probe solution A is only related to Ag. + The fluorescence intensities were almost identical when they coexisted; therefore, it can be inferred from the fluorescence spectrum that the quinoline-based fluorescent probe prepared in this embodiment is effective against Ag. + The fluorescence detection was not interfered with by different types of competing metal ions.

[0029] The probe solution A of Test Example 1 was tested for different Ag. + Concentration response capability, the specific test method is as follows: Add 0~20 µM of Ag at different concentrations to 10 µM probe solution A. + Stock solution. After thorough mixing, sonicate for 5 minutes, then perform fluorescence testing. The results are as follows. Figure 5 As shown. From Figure 5 As can be seen from Ag + As the concentration increases, the fluorescence intensity increases significantly, and the fluorescence emission wavelength gradually red-shifts. Figure 6 This is a linear fitting graph of the fluorescence emission spectrum of Example 1, showing the fluorescence emission intensity versus Ag. + The concentrations are linearly correlated, and the linear equation is y = 0.4126[Ag] + +0.1786, R 2 =0.9991, with a linear range of 0~14 μM.

[0030] The probe solution A of Test Example 1 was tested at different pH values ​​for Ag. + The response capability is tested using the following method: 20 µM Ag is added to probe solution A with a pH of 3-10 and a concentration of 10 µM. + Stock solution. After thorough mixing, sonicate for 5 minutes, then perform fluorescence testing. The results are as follows. Figure 7 As shown. From Figure 7 It can be seen that the F of this probe is within the pH range of 3~10 560 / F 480 The value is low. In Ag + If it exists, the F of KQS 560 / F 480 The effect is significantly enhanced within the pH range of 4–8. However, in strongly acidic or strongly alkaline environments, the F of the probe KQS is significantly reduced. 560 / F 480 The value decreased significantly, indicating that the KQS probe is effective against Ag in the pH range of 4–8. + It has good recognition performance.

[0031] The probe solution A of Test Example 1 was tested at different times for Ag. +The response capability was tested using the following method: 20 µM Ag was added to a 10 µM probe solution A. + Stock solution. The change in fluorescence intensity of probe solution A over time was measured. Results are as follows: Figure 8 As shown. From Figure 8 As can be seen, in the presence of Ag, the fluorescence intensity of the probe decreases rapidly and stops increasing after 30 s, indicating that the probe prepared in this embodiment for Ag... + The quinoline fluorescent probes detected against Ag + It has a relatively fast response speed.

[0032] The probe A in Example 1 tested different Ag values ​​in actual water samples (lake water and industrial wastewater). + The concentration response capability was tested using the following method: Ag solutions prepared with lake water (A) and industrial wastewater (B) at concentrations of 50, 100, 150, 200, and 300 μM were added to probe solution A. + The solution was tested, and the color of probe A solution was recorded under natural light. The results are as follows: Figure 9 As shown in A and 9B. The graph shows that, with Ag... + As the concentration increased, the color of both solutions gradually changed from green to brownish-red.

[0033] Next, using the color recognition function of a smartphone, the color of the probe solution is converted to R / (R+G+B). Since different colors correspond to different Ag... + Concentration, the value of R / (R+G+B) can be obtained as a function of Ag. + The concentration change curves (C corresponds to group A solution; D corresponds to group B solution) allow for the monitoring of Ag using a smartphone. + Rapid and real-time on-site detection. Therefore, it can be inferred that the preparation of this embodiment for Ag... + The quinoline-based fluorescent probes used for detection can detect Ag in actual water samples. + Semi-quantitative analysis was performed.

[0034] The probe A of Example 1 was tested in live mice for its effect on Ag. +The fluorescence imaging capability of KQS was investigated using the following specific method: The cytotoxicity of KQS on live HeLa cells was studied using the MTT assay. Cell viability assay procedure: HeLa cells in logarithmic growth phase were harvested and seeded into 96-well plates. They were incubated at 37°C in a 5% CO2 incubator for 24 h, with fresh DMEM culture medium without the probe serving as the control group. Different concentrations of KQS (0-30 μM) were added to the wells as experimental groups. 100 μL of fresh culture medium and 20 μL of MTT (5 mg / mL) were added to each well, and the cells were incubated at 37°C for another 4 h. The culture supernatant was removed, and the resulting crystals were dissolved in 100 μL of DMSO. The absorbance at 570 nm was measured using a microplate reader. The cytotoxicity experiment was repeated three times. The results are as follows: Figure 10 As shown. From Figure 10 As can be seen from the addition of 10 μM Ag + Afterwards, the cell survival rate was above 80%. Therefore, it can be inferred that the cells prepared in this embodiment for Ag... + The detected quinoline fluorescent probes exhibited low cytotoxicity and good cell membrane permeability.

[0035] The probe A of Example 1 was tested in live mice for its effect on Ag. + The fluorescence imaging capability was tested using the following method: KQS (10 μM, 100 μL) was subcutaneously injected into the leg of a mouse. Subsequently, Ag was injected at the same site. + (2 mM, 25 μL), and fluorescence images were captured at time intervals of 30, 60, and 90 seconds. The results are as follows: Figure 11 As shown. From Figure 11 As can be seen from (A), when Ag is added... + Subsequently, the fluorescence intensity in the mouse's leg gradually decreased. Figure (B) shows the average fluorescence intensity at the injection site. Therefore, it can be inferred that the preparation of this embodiment for Ag... + The quinoline-based fluorescent probes used for detection can be used to detect exogenous Ag in live mice. + Fluorescence imaging.

[0036] Example 2: This example is used for Ag + The preparation method of the quinoline fluorescent probe for detection is carried out according to the following steps: 1. Add 1.1 mmol of quinolinaldehyde monomer and 1 mmol of aminothiourea to 20 mL of methanol solvent I, and then add 0.02 mol of glacial acetic acid as a catalyst. Mix well to obtain reaction solution I. 2. Add reaction solution I to the round-bottom flask, and perform a vacuum-nitrogen-purging cycle on the round-bottom flask to maintain a nitrogen environment inside the round-bottom flask; 3. Raise the temperature of the round-bottom flask to 70°C and maintain it for 9 hours to carry out the reaction; IV. After the reaction was completed, the mixture was cooled to room temperature and filtered. The filter cake was washed clean with a mixed solvent II containing tetrahydrofuran and methanol in a volume ratio of 1:1. After vacuum drying, a Schiff base intermediate with a mass of 0.172 g was obtained. 5. Add 0.5 mmol of Schiff base intermediate and 0.52 mmol of bromoacetophenone to 10 mL of tetrahydrofuran, and react under reflux for 9 hours; VI. After the reaction is complete, the mixture is filtered. The filter cake is washed three times with a mixed solvent II containing tetrahydrofuran and methanol in a volume ratio of 1:1. After vacuum drying, the product is obtained for use with Ag. + The mass of the quinoline fluorescent probe detected was 0.087 g.

[0037] Example 3: This example is used for Ag + The preparation method of the quinoline fluorescent probe for detection is carried out according to the following steps: 1. Add 1.2 mmol of quinolinaldehyde monomer and 1 mol of aminothiourea to 20 mL of toluene solvent I, and then add 0.03 mol of trifluoroacetic acid as a catalyst. Mix well to obtain reaction solution I. 2. Add reaction solution I to the round-bottom flask, and perform a vacuum-nitrogen-purging cycle on the round-bottom flask to maintain a nitrogen environment inside the round-bottom flask; 3. Raise the temperature of the round-bottom flask to 73°C and maintain it for 10 hours to carry out the reaction; IV. After the reaction was completed, the mixture was cooled to room temperature and filtered. The filter cake was washed clean with a mixed solvent II containing acetone and ethyl acetate in a volume ratio of 1:1. After vacuum drying, a Schiff base intermediate with a mass of 0.165 g was obtained. 5. Add 0.5 mmol of Schiff base intermediate and 0.53 mmol of bromoacetophenone to 10 mL of methanol, and react under reflux for 10 hours; VI. After the reaction is complete, the mixture is filtered. The filter cake is washed three times with a mixed solvent II containing ethyl acetate and ethanol in a volume ratio of 1:1. After vacuum drying, the product is obtained for use with Ag. + The mass of the quinoline fluorescent probe detected was 0.082 g.

[0038] Example 4: This example is used for Ag + The preparation method of the quinoline fluorescent probe for detection is carried out according to the following steps: 1. Add 1.3 mol of quinolinaldehyde monomer and 1 mol of aminothiourea to 20 mL of dioxane solvent I, and then add 0.05 mol of p-toluenesulfonic acid as a catalyst. Mix well to obtain reaction solution I. 2. Add reaction solution I to the round-bottom flask, and perform a vacuum-nitrogen-purging cycle on the round-bottom flask to maintain a nitrogen environment inside the round-bottom flask; 3. Raise the temperature of the round-bottom flask to 75°C and maintain it for 11 hours to carry out the reaction; IV. After the reaction was completed, the mixture was cooled to room temperature, filtered, and the filter cake was washed clean with a mixed solvent II containing acetone and methanol in a volume ratio of 1:1. After vacuum drying, a Schiff base intermediate with a mass of 0.171 g was obtained. 5. Add 0.5 mmol of Schiff base intermediate and 0.55 mmol of bromoacetophenone to 10 mL of acetone, and react under reflux for 11 hours. VI. After the reaction is complete, the mixture is filtered. The filter cake is washed three times with a mixed solvent II containing ethanol and acetone in a volume ratio of 1:1. After vacuum drying, the product is obtained for use with Ag. + The detected quinoline fluorescent probe had a mass of 0.088 mg.

[0039] Example 5: This example is used for Ag + The preparation method of the quinoline fluorescent probe for detection is carried out according to the following steps: 1. Add 1.4 mol of quinolinaldehyde monomer and 0.1 mol of aminothiourea to 20 mL of ethanol solvent I, and then add 0.06 mol of concentrated hydrochloric acid with a mass percentage concentration of 30%~37% as a catalyst. Mix well to obtain reaction solution I. 2. Add reaction solution I to the round-bottom flask, and perform a vacuum-nitrogen-purging cycle on the round-bottom flask to maintain a nitrogen environment inside the round-bottom flask; 3. Raise the temperature of the round-bottom flask to 76°C and maintain it for 12 hours to carry out the reaction; IV. After the reaction was completed, the mixture was cooled to room temperature and filtered. The filter cake was washed clean with a mixed solvent II containing tetrahydrofuran and chloroform in a volume ratio of 1:1. After vacuum drying, a Schiff base intermediate with a mass of 0.157 g was obtained. 5. Add 0.5 mmol of Schiff base intermediate and 0.58 mmol of bromoacetophenone to 10 mL of tetrahydrofuran, and react under reflux for 12 hours; VI. After the reaction is complete, the mixture is filtered. The filter cake is washed three times with a mixed solvent II containing ethanol and tetrahydrofuran in a volume ratio of 1:1. After vacuum drying, the product is obtained for use with Ag. + The mass of the quinoline fluorescent probe detected was 0.062 g.

[0040] Example 6: This example is used for Ag + The preparation method of the quinoline fluorescent probe for detection is carried out according to the following steps: 1. Add 1.5 mol of quinolinaldehyde monomer and 1 mol of aminothiourea to 20 mL of methanol solvent I, and then add 0.08 mol of concentrated sulfuric acid with a mass percentage concentration of 95%~98% as a catalyst. Mix well to obtain reaction solution I. 2. Add reaction solution I to the round-bottom flask, and perform a vacuum-nitrogen-purging cycle on the round-bottom flask to maintain a nitrogen environment inside the round-bottom flask; 3. Raise the temperature of the round-bottom flask to 78°C and maintain it for 13 hours to carry out the reaction; IV. After the reaction was completed, the mixture was cooled to room temperature, filtered, and the filter cake was washed clean with a mixed solvent II containing ethanol and acetone in a volume ratio of 1:1. After vacuum drying, a Schiff base intermediate with a mass of 0.160 g was obtained. 5. Add 0.5 mmol of Schiff base intermediate and 0.6 mmol of bromoacetophenone to 10 mL of acetone, and react under reflux for 14 hours; VI. After the reaction is complete, the mixture is filtered. The filter cake is washed three times with a mixed solvent II containing methanol and ethyl acetate in a volume ratio of 1:1. After vacuum drying, the product is obtained for use with Ag. + The mass of the quinoline fluorescent probe detected was 0.077 mg.

[0041] Example 7: This example is used for Ag + The preparation method of the quinoline fluorescent probe for detection is carried out according to the following steps: 1. Add 1.6 mmol of quinolinaldehyde monomer and 1 mmol of aminothiourea to 20 mL of ethanol solvent I, and then add 0.1 mol of glacial acetic acid as a catalyst. Mix well to obtain reaction solution I. 2. Add reaction solution I to the round-bottom flask, and perform a vacuum-nitrogen-purging cycle on the round-bottom flask to maintain a nitrogen environment inside the round-bottom flask; 3. Raise the temperature of the round-bottom flask to 78°C and maintain it for 8 hours to carry out the reaction; IV. After the reaction was completed, the mixture was cooled to room temperature, filtered, and the filter cake was washed clean with a mixed solvent II containing ethanol and chloroform in a volume ratio of 1:1. After vacuum drying, a Schiff base intermediate with a mass of 0.181 g was obtained. 5. Add 0.5 mmol of Schiff base intermediate and 0.75 mmol of bromoacetophenone to 10 mL of methanol, and react under reflux for 10 hours; VI. After the reaction is complete, the mixture is filtered. The filter cake is washed three times with a mixed solvent II containing methanol and tetrahydrofuran in a volume ratio of 1:1. After vacuum drying, the product is obtained for use with Ag. + The mass of the quinoline fluorescent probe detected was 0.084 g.

[0042] Example 8: This example is used for Ag + The preparation method of the quinoline fluorescent probe for detection is carried out according to the following steps: 1. Add 1.7 mmol of quinolinaldehyde monomer and 1 mmol of aminothiourea to 20 mL of ethanol solvent I, and then add 0.07 mol of glacial acetic acid as a catalyst. Mix well to obtain reaction solution I. 2. Add reaction solution I to the round-bottom flask, and perform a vacuum-nitrogen-purging cycle on the round-bottom flask to maintain a nitrogen environment inside the round-bottom flask; 3. Raise the temperature of the round-bottom flask to 78°C and maintain it for 9 hours to carry out the reaction; IV. After the reaction was completed, the mixture was cooled to room temperature and filtered. The filter cake was washed clean with a mixed solvent II containing ethanol and tetrahydrofuran in a volume ratio of 1:1. After vacuum drying, a Schiff base intermediate with a mass of 0.187 g was obtained. 5. Add 0.5 mmol of Schiff base intermediate and 0.63 mmol of bromoacetophenone to 10 mL of anhydrous ethanol, and react under reflux for 11 hours. VI. After the reaction is complete, the mixture is filtered. The filter cake is washed three times with a mixed solvent II containing ethanol and chloroform in a volume ratio of 1:1. After vacuum drying, the product is obtained for use with Ag. + The mass of the quinoline fluorescent probe detected was 0.093 g.

Claims

1. A method for Ag + The quinoline-based fluorescent probe for detection is characterized by, The probe has the following structure:

2. A method for Ag + The method for preparing quinoline fluorescent probes for detection, based on the method for Ag as described in claim 1. + The quinoline-based fluorescent probe for detection is characterized by, This method is performed in the following steps: I. Quinolinaldehyde monomer and aminothiourea are added to solvent I in a molar ratio of (1~2):

1. Then, acid is added to solvent I as a catalyst in a molar ratio of quinolinaldehyde monomer to acid of 1:(0.01~0.1). The mixture is stirred evenly to obtain reaction solution I. The quinolinaldehyde monomer is 6-(dimethylamino)quinoline-2-carboxaldehyde.

2. Add reaction solution I to the round-bottom flask, and perform a vacuum-nitrogen-purging cycle on the round-bottom flask to maintain a nitrogen environment inside the round-bottom flask; 3. Raise the temperature of the round-bottom flask to 60-80℃ and maintain it for 8-14 hours to carry out the reaction; IV. After the reaction is complete, the mixture is cooled to room temperature, filtered, and the filter cake is washed clean with mixed solvent II and dried under vacuum to obtain the Schiff base intermediate.

5. Add the Schiff base intermediate and bromoacetophenone to an organic solvent at a molar ratio of (1~1.3):1, and react under reflux for 8~14 h.

6. After the reaction is complete, filter the mixture, wash the filter cake with mixed solvent II, and dry it under vacuum to obtain a quinoline fluorescent probe for silver ion detection.

3. A method for Ag according to claim 2 + A method for preparing quinoline-based fluorescent probes for detection, characterized in that, Solvent I mentioned in step one is any one of ethanol, methanol, toluene, or dioxane.

4. A method for Ag according to claim 3 + A method for preparing quinoline-based fluorescent probes for detection, characterized in that, The acid mentioned in step one is glacial acetic acid, trifluoroacetic acid, p-toluenesulfonic acid, concentrated hydrochloric acid with a mass percentage concentration of 30% to 37%, or concentrated sulfuric acid with a mass percentage concentration of 95% to 98%.

5. A method for Ag according to claim 3 + A method for preparing quinoline-based fluorescent probes for detection, characterized in that, The molar ratio of the acid to the quinolinaldehyde monomer mentioned in step one is (0.01~0.1):

1.

6. A method for Ag according to claim 3 + A method for preparing quinoline-based fluorescent probes for detection, characterized in that, The mixed solvent II mentioned in steps four and six is ​​any two of tetrahydrofuran, methanol, ethanol, ethyl acetate, acetone, or chloroform.

7. A method for use with Ag according to claim 3 + A method for preparing quinoline-based fluorescent probes for detection, characterized in that, The organic solvent mentioned in step five is tetrahydrofuran, acetone, methanol, or ethanol.

8. Used for Ag + The application of quinoline fluorescent probes for detection, based on the method described in claim 1 for detecting Ag... + The quinoline-based fluorescent probe for detection is characterized by, This application is for Ag + Quinoline-based organic materials were used as fluorescent probes for the detection of Ag. + The detection.

9. The method for Ag according to claim 8 + The application of quinoline-based fluorescent probes for detection is characterized by, Utilizing Ag + The quinoline fluorescent probes used for detection were subjected to Ag + The qualitative detection method is performed according to the following steps: I. To be used for Ag + The quinoline fluorescent probes for detection were uniformly dispersed in a mixture of HEPES buffer solution (pH 7.4) and dimethyl sulfoxide (DMSO) at a volume ratio of 8:2, yielding probe solution A. Probe solution A was then used to detect Ag... + The concentration of the quinoline fluorescent probes used for detection was 5–10 µM; 2. Add the sample to be tested, I, to the probe solution A, mix them evenly, and then obtain the test solution B; III. Using 430 nm as the excitation wavelength, measure the fluorescence emission spectrum of probe solution A, and record the emission intensity at an emission wavelength of 580 nm, denoted as T. A ; IV. Using 430 nm as the excitation wavelength, measure the fluorescence emission spectrum of the test solution B, and record the emission intensity from 480 nm to 560 nm, denoted as T. B ; V. Comparison of T A and T B If T B >T A Then it is determined that the sample to be tested contains Ag. + .

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